Key features and definitions for Explore by Location

Areas of interest (AOI) and markups

An area of interest (AOI) is a specific area on the map that you want to check for overlaps or generate a report. You must have an AOI selected on the map to run a report. 

A markup is when you draw shapes or add text to provide visual cues or notes on the map. Shapes made with the markup tool cannot be used in reports.

Reporting on multiple shapes

You can only run a report on one AOI at a time. If you have a file with multiple, you need to separate them using the Geometry Calculator’s 'explode' option. 

Choosing from two or more AOI

The report will only run on the primary AOI. To choose which one is the primary, use the AOI Metrics toolbar at the bottom right of the map. Select your AOI from the list. The Primary AOI will have a brown outline. 

Reports on points or lines

To run a report on a point or line, use the buffer tool in the Geometry Calculator to create a small area around the point or line before running the report. These reports may not be accurate because they will include the buffer area. 

AOI geometry

The shape or boundaries of a specific area of interest on a map. 

Attribute

A piece of information or characteristic about a map feature, like its size, name or type. 

Base map

The control in the lower right corner of the map determines the display of the base map. 

• Click the up arrow to show all available base maps 
• Click a base map to make it the one displayed
• Click the down arrow to show only the current base map 

Comparison operator

An operator that is used to compare two values and compare their relationship. Example: 2 is less than 4.  

Coordinate

The location of a point on a map, usually given in terms of latitude (north-south) and longitude (east-west). 

Coordinate System (also called Projection)

The spatial reference system in which geometry or feature coordinates are represented. Supported Coordinate Systems include:

• Geographic - May be 'latitude, longitude' or 'longitude, latitude', in either Decimal Degrees (DD) or Degrees-Minutes-Seconds (DMS). Examples are: 
  • DD: 49.5, -125.4 ' 
  • DMS: 49 30' 45", -125 20' 30" 
• BC-Albers - Uses X Y coordinates. Example: 1047118 495805 
• UTM (Universal Transverse Mercator) - Uses X Y and Zone number. Example: 329751 5483095 Zone 10 

Note: British Columbia covers UTM Zones 7-12, so be sure to check this if you choose this option. 

Data format

The way data is organized or saved. Data formats you may see are: 

• KML (*.KML) - Keyhole Markup Language, used in Google Earth 
• GPX (*.GPX) - GPS Exchange format
• GeoJSON (*.JSON) - Geometry expressed in Javascript notation 
• Well-Known Text (*.WKT) - a simple standard geometry format 
• Simple Text (*.TXT) - a text listing of the geometry coordinates 
• GeoMark - the URL or ID of a BC Government GeoMark. Example: http://apps.gov.bc.ca/pub/geomark/geomarks/gm-abcdefghijklmnopqrstuvwxyz0000bc 
• Shapefile (*.SHP) - the ESRI shapefile format
• Mandatory files for a shapefile:
  • .shp: shape format; the feature geometry itself
  • .shx: shape index format; a positional index to allow seeking forwards and backwards  
  • .dbf: attribute format; columnar attributes for each shape, in dBase IV format
• Other common files: 
  • .prj: projection description; text representation of coordinate reference systems  
  • .sbn and .sbx: a spatial index of the features  
  • .shp.xml: geospatial metadata in XML format, such as ISO 19115 or other XML schema  
  • .cpg: used to specify the code page (only for .dbf) for identifying the character encoding 

Distance tolerance

A set distance used to decide when two features on a map are close enough to be considered the same or connected.

Export

The process of saving or transferring map data to a different format or system for use outside the current software. Found under the AOI tools section. 

Features

The different objects or elements on a map, such as rivers, roads or buildings. 

Geographic Coordinate System

A system that uses latitude and longitude to describe locations on the Earth's surface. 

Graticule

A grid of lines representing latitude and longitude, helping to locate places on a map. Turn it on by using the 'Graticule display' button. 

Import

The process of bringing data into a map or mapping software from another source. Found under the AOI tools section. 

Intersections

Points where two or more features (like lines or paths) cross each other on a map. 

Label

Text on a map that identifies a feature, like the name of a city or a river. 

Layers

A set of features with a common business definition. Features in a layer have attributes with the same set of names, but different values. Layers have an associated symbology which specifies how features are displayed on the map. Layer displays may be scale-dependent, so that they only appear in a predefined scale range. 

Layout

The way map elements (title, legend, scale, etc.) are arranged for display or printing. Toggle layers on and off using the Layer button in the top right of the map screen. Get a layout by using the 'Print' function at the top right of your map screen. 

Linear path

A continuous line on a map representing something like a road, river, or boundary. 

Map extent

The area of the map being shown, usually defined by the edges of the visible map view. 

Markup

Adding notes or drawings on a map to highlight or explain certain features.  

Opacity

The degree of transparency or visibility of a layer or element on a map. Use this to balance visibility with background context, with higher transparency for large area features and critical elements at 100 percent opacity.

Note: Opacity is the opposite of transparency. If something is 100 percent opaque, it is zero percent transparent, and vice versa. 

Overlay

A set of layers accessed from a map service. Overlays may be turned on and off and have their opacity changed.

Pan

Moving the map around to look at various parts without changing the zoom level. 

Polygon

A closed shape, usually with multiple sides. 

Query

A way to search for specific data or features on a map, like finding all roads longer than 5 miles. In Explore by Location, use the 'Identify features' button and click anywhere on the map to get information about a layer.

Note: For this tool to work, you need to have the layer turned on.  

Segments

Parts or pieces of a line or shape on a map, such as sections of a road or sides of a polygon. 

Stream digitizing

The process of creating map features that represent streams or rivers by tracing them. 

Style

The settings that decide how things on a map layer look. This is different from symbology because these can be imported and exported between projects as a '.style' file.

Symbol

The symbology used on a map to represent a specific feature, like a star for a city or a line for a river. 

Symbology

The use of symbols, colors and patterns to represent features on a map, making it easier to understand. 

Topology/Topologically

The rules that describe how unique features on a map, like lines, shapes or points are connected and relate to each other. 
Topology can ensure that: 

• Roads are connected at intersections
• Polygons do not self-intersect or overlap when they should not
• Lines (like rivers or roads) do not have gaps between them

Vertex (vertices)

A coordinate point where two line segments meet, forming the structure of a line or polygons.